The oldest evidence of a sauropod dinosaur in the western united states and other important vertebrate trackways from grand staircase‐escalante national monument,Utah

Recent discoveries of abundant fossil footprints from the new Grand Staircase‐Escalante National Monument of southern Utah, have important implications for the spatial and temporal distribution of Mesozoic vertebrates in Triassic and Jurassic time. Since the monument's creation in 1996, fossil footprints have been reported from at least seven formations in the Mesozoic (Triassic‐Cretaceous) within the monument. By far the most significant of these discoveries are sauropod and theropod tracks from the upper part of the Middle Jurassic Entrada Sandstone and a large Apatopus trackway from the Late Triassic Chinle Formation. Tracks in the Entrada Sandstone are found at the same stratigraphic level as those in the Moab megatracksite, and so considerably extend this large ichnological complex. A wide‐gauge sauropod trackway (cf. Brontopodus) from this unit represents the first reported from the Entrada Sandstone, and so is the oldest known from the western United States. This trackway also reveals a tail trace, which is the first reliable record of a sauropod tail trace.     

The earliest evidence of holometabolan insect pupation in conifer wood

Background

The pre-Jurassic record of terrestrial wood borings is poorly resolved, despite body fossil evidence of insect diversification among xylophilic clades starting in the late Paleozoic. Detailed analysis of borings in petrified wood provides direct evidence of wood utilization by invertebrate animals, which typically comprises feeding behaviors.

Methodology/Principal Findings

We describe a U-shaped boring in petrified wood from the Late Triassic Chinle Formation of southern Utah that demonstrates a strong linkage between insect ontogeny and conifer wood resources. Xylokrypta durossi new ichnogenus and ichnospecies is a large excavation in wood that is backfilled with partially digested xylem, creating a secluded chamber. The tracemaker exited the chamber by way of a small vertical shaft. This sequence of behaviors is most consistent with the entrance of a larva followed by pupal quiescence and adult emergence — hallmarks of holometabolous insect ontogeny. Among the known body fossil record of Triassic insects, cupedid beetles (Coleoptera: Archostemata) are deemed the most plausible tracemakers of Xylokrypta, based on their body size and modern xylobiotic lifestyle.

Conclusions/Significance

This oldest record of pupation in fossil wood provides an alternative interpretation to borings once regarded as evidence for Triassic bees. Instead Xylokrypta suggests that early archostematan beetles were leaders in exploiting wood substrates well before modern clades of xylophages arose in the late Mesozoic.     

A Suite of Dermestid Beetle Traces on Dinosaur Bone from the Upper Jurassic Morrison Formation,Wyoming, USA

Most studies of insect traces on fossil bone deal with one or two trace morphs found on isolated bone fragments, making it difficult to identify the trace-maker and its behavior. We report the discovery of a suite of insect traces on an articulated Camptosaurus dinosaur skeleton that permits the identification of the trace-maker and interpretations of its behavior. The traces include mandible marks, pits, and shallow bores on cortical bone, and deep, meandering furrows and tunnels (borings) on articular surfaces. The interiors of bones are intensely mined, and the cavities and borings are filled with fine bone fragments (insect frass). The distinctive mandible marks consist of opposing sets of parallel grooves, indicating the maker had two apical teeth set on symmetrical mandibles and that all of the traces were made by a single taxon. Comparison of the fossils with the mandible morphology and bone traces of extant insects indicates dermestid beetles made the traces. Based on extant dermestid behavior, soft tissues were likely absent and the bones were lipid-laden when the traces were made. Examination of more than 5,000 bones from the Morrison and Cedar Mountain formations shows insect traces on bone are common but overlooked and that many bones are substantially damaged by insect mining. The key to the recognition of these important yet subtle traces is a search model and an intense, oblique light source.     

Considerations on the age of the Tiouaren Formation (Iullemmeden Basin,Niger, Africa): Implications for Gondwanan Mesozoic terrestrial vertebrate faunas

Pre-Aptian mid-Mesozoic terrestrial vertebrates from the African continent are still very poorly known. In Niger, the Tiouaren Formation in the Iullemmeden Basin has yielded dinosaur and other vertebrate remains, and this unit has been dated as Early Cretaceous, most probably pre-Aptian, on the basis of its fish fauna and geological relations to other units in the basin. A review of the fish fauna and invertebrates from this formation does not provide any evidence for such an age, and the geological relations only help to constrain the upper limit for the age of the formation (Aptian). In contrast, the described dinosaur taxa are phylogenetically nested with late Middle Jurassic to Early Late Jurassic taxa from other localities, and thus indicate a pre-Kimmeridgian, probably late Middle Jurassic age for the Tiouaren Formation. Under the assumption of such an age, the dinosaur fauna of this formation provides new insights into dinosaur faunal provincialism during the latest Middle Jurassic. Northern Gondwanan faunas of that time seem to have been different from southern Gondwanan faunas, and show closer affinities to Eurasian faunas than to the latter. A possible explanation for this might be a climatically controlled geographic barrier due to pronounced arid conditions and thus desert environments in central Gondwana during this time.     

First description of axymyiid fossils (Insecta: Diptera: Axymyiidae)

Two species of fossil insects from the Daohugou Formation of Chifeng City in Nei Monggol Autonomous Region, northeastern China are described, and recognized as Psocites pectinatus (Hong, 1983) nov. emend., nov. transl. and P. fossilis nov. sp. They are the oldest representatives of the family Callovian or Axymyiidae, and first described of this family in the Mesozoic. Although early the age of the fly-bearing beds is controversial, it is probably Oxfordian or Kimmeridgian (Late Jurassic) rather than Early Cretaceous or Middle Jurassic.     

Sauropod tracks from the Middle Jurassic Chuanjie Formation of Yunnan Province and the pre-Cretaceous sauropodomorph trackways from China

The Xixipo dinosaur tracksite in the Chuanjie Formation of Yunnan Province is one of the 14 Chinese sites yielding sauropod tracks from between the Triassic–Jurassic and Jurassic–Cretaceous boundaries, but is only one of the two that represent the Middle Jurassic. Although it is a small site, it adds incrementally to the overall track record of the region and allows comparison with the body fossil record and classification of the Chuanjie Formation as a Type 3b or Type 4b deposit in which both the body fossil and trace fossil record, in this case representing sauropodomorphs, are similar in composition and frequency of occurrence. We argue that the sauropod trace and body fossil records, while based on different categories of evidence, are very important. Integrating and correlating all available data from both records increases our understanding of sauropod communities, and both are equally valuable for this. In addition, we also discuss narrow to wide gauge, coeval sauropod trackways from China, and the relationship between the potential trackmaker of China's Jurassic Brontopodus-type trackways and mamenchisaurids and, beginning from the Late Jurassic, representatives of this type and titanosauriform sauropods.     

Fossil coniferous wood from the Middle Jurassic of Liaoning Province, China

Silicified coniferous wood was collected from the Lanqi Formation (late Middle Jurassic in age) at Shebudaigou Village, Liaoning Province, China. Three taxa are identified, namely Pinoxylon dacotense Knowlton, Xenoxylon phyllocladoides Gothan, and Araucariopitys sp. Based on these new data, and those of other fossil plants reported previously from the same formation, we consider the climate during the deposition of the Lanqi Formation was subtropical, humid and seasonal. In this respect the Lanqi flora differs from the coeval Shimengou and Longmen floras from North China. The Longmen flora was deposited during more humid, subtropical conditions, while the Shimengou Formation indicates that the climate was warm temperate and dry. Our data would suggest that the Late Jurassic climatic pattern was initiated as early as the late Middle Jurassic.     

Turtle remains from the Middle Jurassic Xintiangou Formation of Yunyang,Sichuan Basin,China

Three turtle shells from the Middle Jurassic Xintiangou Formation of Yunyang (Chongqing, China) are described and assigned to Xinjiangchelyidae (Testudines: Eucryptodira). This is the first report of turtle remains from the Xintiangou Formation, Sichuan Basin and represents the oldest known Xinjiangchelyidae. The assemblage includes two taxa, Protoxinjiangchelys sp. and Xinjiangchelyidae indet. This discovery extends the stratigraphical distribution of Xinjiangchelyidae and improves our knowledge about the early evolution of that family. It demonstrates that by the Middle Jurassic, at the time of deposition of the Xintiangou Formation, the group was already diversified in the Sichuan Basin.     

The palaeoxylological record of Metapodocarpoxylon libanoticum (Edwards) Dupéron-Laudoueneix et Pons and the Gondwana Late Jurassic–Early Cretaceous continental biogeography

Aim Vertebrates, palynomorphs and leaf floras each give a different picture of continental biogeography of Northern Gondwana during the Middle Jurassic–Early Cretaceous interval. A new biogeographical marker is required to get a clearer picture. Location Northern part of the Gondwana during the Middle Jurassic–Early Cretaceous interval. Methods Comparisons and correlations of wood data from the literature and new material. Results We have selected Metapodocarpoxylon Dupéron‐Laudoueneix et Pons because it has a restricted distribution, temporally and geographically; it is a well‐defined Mesozoic fossil wood monospecific genus, and there are wide‐ranging data on its distribution. Conclusions Metapodocarpoxylon distribution draws a clear latitudinal belt extending from Lebanon westward to Peru. Climate being the main factor of plant distribution at a global scale, the Metapodocarpoxylon area probably underlines a climatic belt. This has several implications, for example, choosing among different Global Circulation Models or discussing dinosaur distribution.     

The Trace Fossil Paleodictyon within The Cruziana Ichnofacies: First Record from The Devonian in Pennsylvania

Offshore marine deposits of hemipelagic dark-gray shales comprising the Middle Devonian Mahantango Formation have yielded the first evidence of the trace fossil Paleodictyon from Pennsylvania. Paleodictyon occurs in conjunction with a diversity of largely deposit-feeding trace fossils belonging to the Cruziana ichnofacies, and documents another example of a shallower-water occurrence of this ichnofossil in Paleozoic rocks.     

Dispersal and diversity in the earliest North American sauropodomorph dinosaurs, with a description of a new taxon

Sauropodomorph dinosaurs originated in the Southern Hemisphere in the Middle or Late Triassic and are commonly portrayed as spreading rapidly to all corners of Pangaea as part of a uniform Late Triassic to Early Jurassic cosmopolitan dinosaur fauna. Under this model, dispersal allegedly inhibited dinosaurian diversification, while vicariance and local extinction enhanced it. However, apomorphy-based analyses of the known fossil record indicate that sauropodomorphs were absent in North America until the Early Jurassic, reframing the temporal context of their arrival. We describe a new taxon from the Kayenta Formation of Arizona that comprises the third diagnosable sauropodomorph from the Early Jurassic of North America. We analysed its relationships to test whether sauropodomorphs reached North America in a single sweepstakes event or in separate dispersals. Our finding of separate arrivals by all three taxa suggests dispersal as a chief factor in dinosaurian diversification during at least the early Mesozoic. It questions whether a 'cosmopolitan' dinosaur fauna ever existed, and corroborates that vicariance, extinction and dispersal did not operate uniformly in time or under uniform conditions during the Mesozoic. Their relative importance is best measured in narrow time slices and circumscribed geographical regions.     

New dinosaur tracksites from the Middle Jurassic of Madagascar: ichnotaxonomical,behavioural and palaeoenvironmental implications

Abstract: New dinosaur tracksites are described from the Bajocian–Bathonian Bemaraha Formation of western Madagascar. Two track‐bearing surfaces can be followed over a distance of at least 4 km, suggesting the existence of a hitherto unrecognized megatracksite. The track assemblage is theropod dominated, but sauropod tracks also occur at one site. Qualitative and quantitative analysis of the abundant theropod track material suggests that most, if not all, theropod footprints are attributable to a single trackmaker and are referred to Kayentapus isp. Although this ichnogenus, originally described from the Lower Jurassic of North America, has never been recorded from Gondwana nor from the Middle Jurassic, track morphology strongly suggests this attribution. Palaeogeographical, sedimentological and ichnological data suggest that the dinosaur tracks formed in an intertidal to supratidal setting where the coastline influenced the preferred walking direction of the animals.     

New fossil mantidflies (Insecta: Neuroptera: Mantispidae) from the Mesozoic of north‐eastern China

Abstract:  Three new genera and four new species of the extinct mantidfly subfamily Mesomantispinae (Insecta: Neuroptera: Mantispidae) are described from the Lower Cretaceous Yixian Formation of Liaoning and the Middle Jurassic Jiulongshan Formation of Inner Mongolia: Archaeodrepanicus nuddsi gen. et sp. nov., A. acutus gen. et sp. nov., Sinomesomantispa microdentata gen. et sp. nov., (Yixian Formation) and Clavifemora rotundata gen. et sp. nov. (Jiulongshan Formation). The specimens described herein represent the first Mesozoic mantidfly compression fossils to have body parts preserved, including the specialized raptorial forelegs articulated to the prothorax anteriorly, an autapomorphy of the family. These new taxa further confirm the placement of the subfamily Mesomantispinae within the family Mantispidae; however, the monophyly of Mesomantispinae has not been confirmed, and it is likely that it will prove to be paraphyletic.     

New Phoenicopsis leaves (Czekanowskiales) from the Middle Jurassic Daohugou Biota,China and their roles in phytogeographic and paleoclimatic reconstruction

The Middle Jurassic Jiulongshan Formation, distributed in the Daohugou area, Ningcheng County, Inner Mongolia, China, is famous for yielding abundant, well-preserved fossil vertebrates and invertebrates. However, only a few fossil plants have been reported to date. In this paper, one new species of Czekanowskiales, Phoenicopsis (Windwardia) daohugouensis n. sp. is described based upon leaf morphology and epidermal characters. The new species represents the first record of Czekanowskiales from the Daohugou Biota. The discovery of the new species reveals the significance of the Daohugou flora as one of the deciduous forests in the temperate-warm temperate zone of Eurasia during the Middle Jurassic.     

Study on the Fossil Woods Found in Zigong,Sichuan, China

This paper describes three fossil woods, which were firstly found in Zigong city, Sichuan Province, China. The localities of the fossil woods are close to the locality of the famous Dashanpu dinosaur quarry of Zigong. The strata of the fossil woods beating are Xiashaximiao Formation and Xintiangou Formation of the Middle Jurassic, approximately match the strata of the Dashanpu dinosaurs. According to the structures of the secondary xylem, the fossil woods belonged to the primitive conifer genus-Araucarioxylon. Because it was comparatively and obviously different from the other species in this genus, it is assigned as a new species: A. zigongensis. As there was neither fossil leaf nor fossil pollen or spore found in the dinosaur bearing strata before, the discovery of these fossil woods might bear some important significance in the dinosaur research.     

Host‐specific acrothoracid barnacles on Middle Devonian platyceratid gastropods

Borings, attributed to acrothoracic barnacles, occur on the platyceratid gastropod Naticonema lineatum (Conrad) from the Middle Devonian Hamilton Group of western New York and rarely in specimens as old as the Early Devonian. These latter are the oldest known acrothoracid borings are in the fossil record. The borings are consistently developed as laterally compressed, inequilateral pouches exclusively on these gastropods, commonly as dense infestations.

Naticonema shells yielding borings typically occur associated with partially articulated qrinoid remains, and they are sometimes found attached to crinoids in a manner similar to coprophagous Platyceras. In addition to barnacle borings, Naticonema shells often bear thin encrustations of bryozoans which are usually perforated by these borings but sometimes also overgrow them. Barnacles bored live hosts; gastropods prevented shell penetration by producing cyst‐like secondary secretions of calcite beneath acrothoracid boreholes.

The relative antiquity of these borings and their association with coprophagous platyceratids makes their discovery particularly significant in revealing aspects of the early ecology of barnacles. Attachment to the host commensal gastropods was one of the first successful life modes of these crustaceans prior to their later diversification to other habitats. Mississippian and Pennsylvanian occurrences of similarly bored gastropods demonstrate continuity of the barnacle‐gastropod‐crinoid ecological association from the Middle to Late Paleozoic.     

Sauropod and Small Theropod Tracks from the Lower Jurassic Ziliujing Formation of Zigong City,Sichuan, China,with an Overview of Triassic–Jurassic Dinosaur Fossils and Footprints of the Sichuan Basin

A dinosaur footprint assemblage from the Lower Jurassic Ziliujing Formation of Zigong City, Sichuan, China, comprises about 300 tracks of small tridactyl theropods and large sauropods preserved as concave epireliefs (natural molds). The theropod footprints show similarities with both the ichnogenera Grallator and Jialingpus. Three different morphotypes are present, probably related to different substrate conditions and extramorphological variation. A peculiar preservational feature in a morphotype that reflects a gracile trackmaker with extremely slender digits, is the presence of a convex epirelief that occurs at the bottom of the concave digit impressions. It is possibly the result of sediment compaction underweight load when the pes penetrated the substrate, being a resistant residue during exhumation and weathering. The sauropod tracks belong to a trackway with eight imprints consisting of poorly preserved pes and manus tracks and a better preserved set, probably all undertracks. The narrow-gauge trackway pattern resembles the ichnogenus Parabrontopodus well known from the Jurassic but other features such as the minor heteropody are different. The assemblage enriches the dinosaur record from the famous Zigong locality and the evidence from the Lower Jurassic in this area that was restricted to a few skeletal remains and footprints. Furthermore it proves the presence of small theropods, whereas skeletons of the group, well- known from the Middle-Upper Jurassic of Zigong, are of medium to large size only. Remarkable is the dominance of saurischians in these assemblages, which is characteristic of Jurassic dinosaur communities whereas the Cretaceous record shows an increase of ornithopod groups. An overview of the dinosaur trace and body fossil record of the Sichuan Basin supports this view. The paleoenvironment can be designated as a low-latitude tropical freshwater lake as it is indicated by bivalve shells.     

A diverse Upper Jurassic dinosaur ichnofauna from central‐west Portugal

Mateus, O. & Milàn, J. 2009: A diverse Upper Jurassic dinosaur ichnofauna from central‐west Portugal. Lethaia, Vol. 43, pp. 245–257. A newly discovered dinosaur track‐assemblage from the Upper Jurassic Lourinhã Formation (Lusitanian Basin, central‐west Portugal), comprises medium‐ to large‐sized sauropod tracks with well‐preserved impressions of soft tissue anatomy, stegosaur tracks and tracks from medium‐ to large‐sized theropods. The 400‐m‐thick Lourinhã Formation consists of mostly aluvial sediments, deposited during the early rifting of the Atlantic Ocean in the Kimmeridgian and Tithonian. The stratigraphic succession shows several shifts between flood‐plain mud and fluvial sands that favour preservation and fossilization of tracks. The studied track‐assemblage is found preserved as natural casts on the underside of a thin bivalve‐rich carbonate bed near the Tithonian–Kimmeridgian boundary. The diversity of the tracks from the new track assemblage is compared with similar faunas from the Upper Jurassic of Asturias, Spain and the Middle Jurassic Yorkshire Coast of England. The Portuguese record of Upper Jurassic dinosaur body fossils show close similarity to the track fauna from the Lourinhã Formation. □Dinosaur tracks, Lusitanian Basin, Portugal, skin impressions, Upper Jurassic.